.slot {
    background: aquamarine;
    padding: 10px;
    margin: 10px;
}
.flex-sub {
    width: 50px;
    height: 50px;
    background: seagreen;
    line-height: 50px;
    margin: 5px;
}
.flex-sub-in-bb {
    background: seagreen;
    color: white;
}
